The present invention relates to a movement or proximity detection switching device, including a sensitive component to carry out this detection, and a body defining a housing for a switch assembly controlled by the sensitive component and connected to the outside via an electrical connection cable, the housing being closed by a removable cover.
Description of Prior Art
Limit or safety switches for industrial use are well known (for example XCK-J products, see Telemecanique catalogue xe2x80x9cLimit switchesxe2x80x9d, April 1999). Cabling the contact block of such devices is difficult and the different devices in a range require different casings when it is required to connect to these casings cables of different diameters or to add to these casings cable entries equipped with different threads.
The document WO-99/27 551 shows a limit switch wherein the body and the cover each have a threaded half flange to receive a maiden nut of a seal coupling. The effect of tightening the nut is to distort or reposition the cover, which corrupts the seal qualities of the device.
The purpose of the invention is to make it easier to assemble and to cable, in the body of such devices, a switching block equipped with connection elements, ensuring the assembly is well sealed, while allowing cables of different diameters or couplings with different characteristics to be used without modifying the body.
According to the invention, the detachable cable entry coupling is introduced by means of fitting elements, by a sliding movement along a direction approximately perpendicular to the main wall of the cover, in guiding and holding means provided in the body. It is possible in this way to add to a same device body couplings which are differentiated by their internal diameter or by their thread type.
The guiding and holding means of the body are preferably rectilinear and the fitting elements of the coupling form a frame fitted on its sides with insertion means complementing the guiding and holding means, the switching block and the coupling being introduced into the device body in a same direction. The frame is to advantage symmetrical, located at the end of the coupling and housed partly in the housing of the switching block and partly in guiding and holding means provided in the cover.
The coupling carries an external seal and the cover is mounted on the body by means of pivoting elements, preferably hooks, provided near one end and has at the other end a screw for fixing to the body, the pivoting elements being offset relative to the plane of the main wall of the cover so as to increase the tightening torque of the seal.